Brake



` April 28 1942 R, GoEPFRlcH 2,281,150

BRAKE Filed Aug. 17, 1939 INVENTOR. /faazP//A 6050/99/66/ BY d E y ATTORNEY Patented Apr. 1942 Balma `Rudolph A. .Goepfricn south Bend, Ind., ass-mor to. Bendix Aviation Corporation, South Bend,

Ind., a corporationoi Y 6 Claims.

This invention relates to brakes, and is illustrated as embodied in an internal expanding brake for an automobile. Y Anobject of the invention is to provide simple and reliable automatic means `for adjusting `the brake for weer or the brakeuning; without eiect from variations in the size of theV brake" Delaware Application August 17. 1939, Serial No. 290,547`

drum as it expands and contracts when heated and cooled. To this endthe adjustment means is of the type which is operated by the drum act;` ing on one end of a plungeror the equivalent, carried bythe brake shoe, so that the clearance of the brake when released is determined'by di rect measurement from the braking surface of drawing, in which:

Figure l is avertical section through the brake,

just inside the head of the brake drum, and showlng the shoes in side elevation;

Figures 2 and 3 are partial sections on the lines 2-2 and 3-f3 of Figure 1.

The brake illustrated in Figures l3 comprises a rotatable drum IIL-at the open side of which is a support such as a backingplate I2. The illustrated friction means comprises two shoes I4 and i6, T-shaped in section to provide 'stiftening webs and outer rims faced with brake lining, and which are adjustably mounted at their lower brake is applied, against the resistance of a return spring 2U, by means such as a hydraulic wheel cylinder 22 within which are largeand small pistons 24` and 26 acting on the upper ends of the shoes.

When used on the rear wheels, the brakes may also be used as the -emergency brakes, and are then provided also with mechanical applying means. The brake shown has a lever 28 pivoted on one shoe and connected to the other by` a lthrust memberlll, the lever being actuated by the cable 32 of a Bowden-type control'.

The shoe I 6 is provided with a steady rest com-l prising a `stumped U-section clip 34 embracing (Cl. 18S-79.5)

the'web, and one arm of which has an opening to receive the bent-over endo! a leaf spring ll Shoe I4 is secured to the backing plate. The provided with a steady rest comprising a stamp` ing 38 `formed to embrace the shoe web and which is engaged by a looped-over leaf `spring 4l, and

which has secured thereto aleaf spring 42 serv' ing as a steady rest for the lever 2li.` i

Each of the shoes has a plunger, or equivalent memben 4B `engaging one sideof its web and ar ranged with its outer portion passing through aimed slots of correspondingshape.` `The end or plunger 46 is ush with the surface of the brake lining facing the shoe, and is forced against the drum when the brake'is applied, in such a man-- ner' as to shift the plunger inwardly if thelining has worn.

Each plunger 46 is pivotally connected toand mounted on a pin 48 extending eccentric-ally integrally from the end of a member 50 ofvcircular outline, which is rotatably mounted in a hole in the shoe web. On the opposite side of the web f from the plunger 46 there is ilxed on member l0 t ends on eccentric adjustable anchors i8. The A (for example by pressing it on) a cam 52 of stamped steel having an edge ilange which engages l(when the brake is released) an eccentric adjustable and normally fixed stop 54. A spring washer 5S engaging a groove in the end of pin 48 engages the plunger 48 and serves to hold it frictionally against shifting except when focred inwardly by the brake drum.

In operation, each plunger 46 is gradually shifted inwardly -by the drum as the brake lining Wears, and turns the cam 52 to adjust ,the released position of the shoe to correspond to the wear.

p As the above adjustment is actuated to compensate for lining wear, the pressure in the livdraulic lines, together with a spring 'l2 between them, holds the pistons 24 and 2C out against the shoes `so thatthe volume or the hydraulic system is automatically increased to compensate for the shoe adjustment.

While an illustrative structurehas been described in' detail, it is not my intention to limit the scope of the invention to that structure, or otherwise than by the terms of the appended claims.

I claim:

1. A brake having. for use in combination with a brake drum, a shoe having movaly mounted thereon a member shifted by said drum when the brake is applied after the shoe has worn. a member rotatably mounted on the shoe and which has eccentrically arranged means pivotally l connecting it` to ythe nrst member, a positioning device mounted on the rotatable member, and a positioning device engaged by the first device when the brake is released.

2. A brake having, for use in combination with a brake drum, a shoe having movably mounted thereon a member shifted by said drum when the brake is applied after the shoe has worn, a member rotatably mounted on theshoe and 'whichV is turned by shifting of the iirst member,v and means for progressively moving the rotatable member toward the brake drum comprising a cam rigidly mounted on the rotatable member v and a fixed stop engaged by the cam when the Y brake is released. I

3. A brake shoe having a web and a rim faced with brake lining, a plunger on one side of the web extending at its end through openings in the rim and lining, a member having a part rotatably arranged in the web and having a pin extending eccentrically therefrom and `which pin plvotally engages said plunger, a cam` fixed on said memberr on the other side of the web from V theplunger. avpositioning device cooperating at times withV saidcam'and aspring device engag-v ing thepin and said plunger and urging the plungeragainst saidweb. p

4. A brake shoe han a `web and ak rim faced with brake a vplunger on one side of the web`,extending at lits end through openings in the rim andlining, almemberghaving a part ro-Y plunger .against said web.`

4 changed.

5. A brake having, for use in combination with a brake drum, a shoe having movably mountedV thereon a member shifted by said drum when the brake is applied after the shoe has worn, a member rotatably mounted on the shoe and which is turned by shifting of the first member, and a positioning device comprising a plurality of cooperating elements one mounted lon the rotatable member and a second engaged by the first when the brake is released, atleast one of said elements being movable to change the points of contact between the elements and at least one of said elements having a cam shaped surface so as to accomplish adjustment of the brake by moving the shoe toward the drum whenever the points of contact between the elements are changed. Y

6. A brake having, for usein' combination with a brake drum, a shoefhaving movably mounted thereon 'a member shifted by said drum when the brake is applied after the shoe has worn, a

member rotatably mounted on the shoe and pivf otally connected to the first member, and a positonlng device comprising a plurality of cooper@ ating elements one mounted `on the rotatable member and a second engaged by the rst when the brake is released, at least one .of said ele--` ments being movable to change thepoints `of contact between the elementsand at least one of said elements having a cam shaped surfaceso as .to accomplish adjustment of the brake by moving the shoe toward the drum whenever the points of contact, between the elements are RUnOLPH A. GOEPFRICH. 

